1 files changed, 99 insertions, 44 deletions

diff --git a/mm/shmem.c b/mm/shmem.c
index eef4ebea515..f65f84062db 100644
--- a/mm/shmem.c
+++ b/mm/shmem.c
@@ -433,8 +433,6 @@ static swp_entry_t *shmem_swp_alloc(struct shmem_inode_info *info, unsigned long
 
 		spin_unlock(&info->lock);
 		page = shmem_dir_alloc(mapping_gfp_mask(inode->i_mapping));
-		if (page)
-			set_page_private(page, 0);
 		spin_lock(&info->lock);
 
 		if (!page) {
@@ -729,10 +727,11 @@ done2:
 	if (inode->i_mapping->nrpages && (info->flags & SHMEM_PAGEIN)) {
 		/*
 		 * Call truncate_inode_pages again: racing shmem_unuse_inode
-		 * may have swizzled a page in from swap since vmtruncate or
-		 * generic_delete_inode did it, before we lowered next_index.
-		 * Also, though shmem_getpage checks i_size before adding to
-		 * cache, no recheck after: so fix the narrow window there too.
+		 * may have swizzled a page in from swap since
+		 * truncate_pagecache or generic_delete_inode did it, before we
+		 * lowered next_index.  Also, though shmem_getpage checks
+		 * i_size before adding to cache, no recheck after: so fix the
+		 * narrow window there too.
 		 *
 		 * Recalling truncate_inode_pages_range and unmap_mapping_range
 		 * every time for punch_hole (which never got a chance to clear
@@ -762,19 +761,17 @@ done2:
 	}
 }
 
-static void shmem_truncate(struct inode *inode)
-{
-	shmem_truncate_range(inode, inode->i_size, (loff_t)-1);
-}
-
 static int shmem_notify_change(struct dentry *dentry, struct iattr *attr)
 {
 	struct inode *inode = dentry->d_inode;
-	struct page *page = NULL;
+	loff_t newsize = attr->ia_size;
 	int error;
 
-	if (S_ISREG(inode->i_mode) && (attr->ia_valid & ATTR_SIZE)) {
-		if (attr->ia_size < inode->i_size) {
+	if (S_ISREG(inode->i_mode) && (attr->ia_valid & ATTR_SIZE)
+					&& newsize != inode->i_size) {
+		struct page *page = NULL;
+
+		if (newsize < inode->i_size) {
 			/*
 			 * If truncating down to a partial page, then
 			 * if that page is already allocated, hold it
@@ -782,9 +779,9 @@ static int shmem_notify_change(struct dentry *dentry, struct iattr *attr)
 			 * truncate_partial_page cannnot miss it were
 			 * it assigned to swap.
 			 */
-			if (attr->ia_size & (PAGE_CACHE_SIZE-1)) {
+			if (newsize & (PAGE_CACHE_SIZE-1)) {
 				(void) shmem_getpage(inode,
-					attr->ia_size>>PAGE_CACHE_SHIFT,
+					newsize >> PAGE_CACHE_SHIFT,
 						&page, SGP_READ, NULL);
 				if (page)
 					unlock_page(page);
@@ -796,24 +793,29 @@ static int shmem_notify_change(struct dentry *dentry, struct iattr *attr)
 			 * if it's being fully truncated to zero-length: the
 			 * nrpages check is efficient enough in that case.
 			 */
-			if (attr->ia_size) {
+			if (newsize) {
 				struct shmem_inode_info *info = SHMEM_I(inode);
 				spin_lock(&info->lock);
 				info->flags &= ~SHMEM_PAGEIN;
 				spin_unlock(&info->lock);
 			}
 		}
+
+		error = simple_setsize(inode, newsize);
+		if (page)
+			page_cache_release(page);
+		if (error)
+			return error;
+		shmem_truncate_range(inode, newsize, (loff_t)-1);
 	}
 
 	error = inode_change_ok(inode, attr);
 	if (!error)
-		error = inode_setattr(inode, attr);
+		generic_setattr(inode, attr);
 #ifdef CONFIG_TMPFS_POSIX_ACL
 	if (!error && (attr->ia_valid & ATTR_MODE))
 		error = generic_acl_chmod(inode);
 #endif
-	if (page)
-		page_cache_release(page);
 	return error;
 }
 
@@ -821,11 +823,11 @@ static void shmem_delete_inode(struct inode *inode)
 {
 	struct shmem_inode_info *info = SHMEM_I(inode);
 
-	if (inode->i_op->truncate == shmem_truncate) {
+	if (inode->i_mapping->a_ops == &shmem_aops) {
 		truncate_inode_pages(inode->i_mapping, 0);
 		shmem_unacct_size(info->flags, inode->i_size);
 		inode->i_size = 0;
-		shmem_truncate(inode);
+		shmem_truncate_range(inode, 0, (loff_t)-1);
 		if (!list_empty(&info->swaplist)) {
 			mutex_lock(&shmem_swaplist_mutex);
 			list_del_init(&info->swaplist);
@@ -1545,8 +1547,8 @@ static int shmem_mmap(struct file *file, struct vm_area_struct *vma)
 	return 0;
 }
 
-static struct inode *shmem_get_inode(struct super_block *sb, int mode,
-					dev_t dev, unsigned long flags)
+static struct inode *shmem_get_inode(struct super_block *sb, const struct inode *dir,
+				     int mode, dev_t dev, unsigned long flags)
 {
 	struct inode *inode;
 	struct shmem_inode_info *info;
@@ -1557,9 +1559,7 @@ static struct inode *shmem_get_inode(struct super_block *sb, int mode,
 
 	inode = new_inode(sb);
 	if (inode) {
-		inode->i_mode = mode;
-		inode->i_uid = current_fsuid();
-		inode->i_gid = current_fsgid();
+		inode_init_owner(inode, dir, mode);
 		inode->i_blocks = 0;
 		inode->i_mapping->backing_dev_info = &shmem_backing_dev_info;
 		inode->i_atime = inode->i_mtime = inode->i_ctime = CURRENT_TIME;
@@ -1814,7 +1814,7 @@ shmem_mknod(struct inode *dir, struct dentry *dentry, int mode, dev_t dev)
 	struct inode *inode;
 	int error = -ENOSPC;
 
-	inode = shmem_get_inode(dir->i_sb, mode, dev, VM_NORESERVE);
+	inode = shmem_get_inode(dir->i_sb, dir, mode, dev, VM_NORESERVE);
 	if (inode) {
 		error = security_inode_init_security(inode, dir, NULL, NULL,
 						     NULL);
@@ -1833,11 +1833,6 @@ shmem_mknod(struct inode *dir, struct dentry *dentry, int mode, dev_t dev)
 #else
 		error = 0;
 #endif
-		if (dir->i_mode & S_ISGID) {
-			inode->i_gid = dir->i_gid;
-			if (S_ISDIR(mode))
-				inode->i_mode |= S_ISGID;
-		}
 		dir->i_size += BOGO_DIRENT_SIZE;
 		dir->i_ctime = dir->i_mtime = CURRENT_TIME;
 		d_instantiate(dentry, inode);
@@ -1957,7 +1952,7 @@ static int shmem_symlink(struct inode *dir, struct dentry *dentry, const char *s
 	if (len > PAGE_CACHE_SIZE)
 		return -ENAMETOOLONG;
 
-	inode = shmem_get_inode(dir->i_sb, S_IFLNK|S_IRWXUGO, 0, VM_NORESERVE);
+	inode = shmem_get_inode(dir->i_sb, dir, S_IFLNK|S_IRWXUGO, 0, VM_NORESERVE);
 	if (!inode)
 		return -ENOSPC;
 
@@ -1992,8 +1987,6 @@ static int shmem_symlink(struct inode *dir, struct dentry *dentry, const char *s
 		unlock_page(page);
 		page_cache_release(page);
 	}
-	if (dir->i_mode & S_ISGID)
-		inode->i_gid = dir->i_gid;
 	dir->i_size += BOGO_DIRENT_SIZE;
 	dir->i_ctime = dir->i_mtime = CURRENT_TIME;
 	d_instantiate(dentry, inode);
@@ -2033,7 +2026,6 @@ static const struct inode_operations shmem_symlink_inline_operations = {
 };
 
 static const struct inode_operations shmem_symlink_inode_operations = {
-	.truncate	= shmem_truncate,
 	.readlink	= generic_readlink,
 	.follow_link	= shmem_follow_link,
 	.put_link	= shmem_put_link,
@@ -2071,14 +2063,14 @@ static int shmem_xattr_security_set(struct dentry *dentry, const char *name,
 					  size, flags);
 }
 
-static struct xattr_handler shmem_xattr_security_handler = {
+static const struct xattr_handler shmem_xattr_security_handler = {
 	.prefix = XATTR_SECURITY_PREFIX,
 	.list   = shmem_xattr_security_list,
 	.get    = shmem_xattr_security_get,
 	.set    = shmem_xattr_security_set,
 };
 
-static struct xattr_handler *shmem_xattr_handlers[] = {
+static const struct xattr_handler *shmem_xattr_handlers[] = {
 	&generic_acl_access_handler,
 	&generic_acl_default_handler,
 	&shmem_xattr_security_handler,
@@ -2366,7 +2358,7 @@ int shmem_fill_super(struct super_block *sb, void *data, int silent)
 	sb->s_flags |= MS_POSIXACL;
 #endif
 
-	inode = shmem_get_inode(sb, S_IFDIR | sbinfo->mode, 0, VM_NORESERVE);
+	inode = shmem_get_inode(sb, NULL, S_IFDIR | sbinfo->mode, 0, VM_NORESERVE);
 	if (!inode)
 		goto failed;
 	inode->i_uid = sbinfo->uid;
@@ -2444,14 +2436,13 @@ static const struct file_operations shmem_file_operations = {
 	.write		= do_sync_write,
 	.aio_read	= shmem_file_aio_read,
 	.aio_write	= generic_file_aio_write,
-	.fsync		= simple_sync_file,
+	.fsync		= noop_fsync,
 	.splice_read	= generic_file_splice_read,
 	.splice_write	= generic_file_splice_write,
 #endif
 };
 
 static const struct inode_operations shmem_inode_operations = {
-	.truncate	= shmem_truncate,
 	.setattr	= shmem_notify_change,
 	.truncate_range	= shmem_truncate_range,
 #ifdef CONFIG_TMPFS_POSIX_ACL
@@ -2570,6 +2561,45 @@ out4:
 	return error;
 }
 
+#ifdef CONFIG_CGROUP_MEM_RES_CTLR
+/**
+ * mem_cgroup_get_shmem_target - find a page or entry assigned to the shmem file
+ * @inode: the inode to be searched
+ * @pgoff: the offset to be searched
+ * @pagep: the pointer for the found page to be stored
+ * @ent: the pointer for the found swap entry to be stored
+ *
+ * If a page is found, refcount of it is incremented. Callers should handle
+ * these refcount.
+ */
+void mem_cgroup_get_shmem_target(struct inode *inode, pgoff_t pgoff,
+					struct page **pagep, swp_entry_t *ent)
+{
+	swp_entry_t entry = { .val = 0 }, *ptr;
+	struct page *page = NULL;
+	struct shmem_inode_info *info = SHMEM_I(inode);
+
+	if ((pgoff << PAGE_CACHE_SHIFT) >= i_size_read(inode))
+		goto out;
+
+	spin_lock(&info->lock);
+	ptr = shmem_swp_entry(info, pgoff, NULL);
+#ifdef CONFIG_SWAP
+	if (ptr && ptr->val) {
+		entry.val = ptr->val;
+		page = find_get_page(&swapper_space, entry.val);
+	} else
+#endif
+		page = find_get_page(inode->i_mapping, pgoff);
+	if (ptr)
+		shmem_swp_unmap(ptr);
+	spin_unlock(&info->lock);
+out:
+	*pagep = page;
+	*ent = entry;
+}
+#endif
+
 #else /* !CONFIG_SHMEM */
 
 /*
@@ -2609,9 +2639,34 @@ int shmem_lock(struct file *file, int lock, struct user_struct *user)
 	return 0;
 }
 
+#ifdef CONFIG_CGROUP_MEM_RES_CTLR
+/**
+ * mem_cgroup_get_shmem_target - find a page or entry assigned to the shmem file
+ * @inode: the inode to be searched
+ * @pgoff: the offset to be searched
+ * @pagep: the pointer for the found page to be stored
+ * @ent: the pointer for the found swap entry to be stored
+ *
+ * If a page is found, refcount of it is incremented. Callers should handle
+ * these refcount.
+ */
+void mem_cgroup_get_shmem_target(struct inode *inode, pgoff_t pgoff,
+					struct page **pagep, swp_entry_t *ent)
+{
+	struct page *page = NULL;
+
+	if ((pgoff << PAGE_CACHE_SHIFT) >= i_size_read(inode))
+		goto out;
+	page = find_get_page(inode->i_mapping, pgoff);
+out:
+	*pagep = page;
+	*ent = (swp_entry_t){ .val = 0 };
+}
+#endif
+
 #define shmem_vm_ops				generic_file_vm_ops
 #define shmem_file_operations			ramfs_file_operations
-#define shmem_get_inode(sb, mode, dev, flags)	ramfs_get_inode(sb, mode, dev)
+#define shmem_get_inode(sb, dir, mode, dev, flags)	ramfs_get_inode(sb, dir, mode, dev)
 #define shmem_acct_size(flags, size)		0
 #define shmem_unacct_size(flags, size)		do {} while (0)
 #define SHMEM_MAX_BYTES				MAX_LFS_FILESIZE
@@ -2655,7 +2710,7 @@ struct file *shmem_file_setup(const char *name, loff_t size, unsigned long flags
 	path.mnt = mntget(shm_mnt);
 
 	error = -ENOSPC;
-	inode = shmem_get_inode(root->d_sb, S_IFREG | S_IRWXUGO, 0, flags);
+	inode = shmem_get_inode(root->d_sb, NULL, S_IFREG | S_IRWXUGO, 0, flags);
 	if (!inode)
 		goto put_dentry;